The invention relates to a sports shoe, in particular a soccer boot, comprising a sole which is made of plastic and has on its underside at least one carrier surface which is configured raised, in each of which surfaces at least two threaded inserts being embedded that serve for receiving traction elements capable of being screwed in.
Such sports or casual shoes, which comprise screw-in studs or spikes as traction elements capable of being screwed in, have been known for a long time. In case of damage, these studs or spikes can be replaced in a relatively easy manner, but only by studs and spikes of the same type and size, which are available as a spare part set matching with the type of sports shoe concerned.
From DE-A-44 17 563 there is known a soccer boot comprising a sole which is equipped not only with exchangeable screw-in studs or cams, but additionally with a second type of traction elements, namely elongate, wedge-shaped gripping elements which are arranged primarily along the edge of the sole and enhance the jump- and acceleration power of a soccer player by ensuring an improved security against slipping and an improved anchoring of the shoe in the ground.
From EP-A-0 533 570 there is known a sports shoe sole for sports shoes, on the underside of which several reinforcement plates are provided in which traction elements, preferably spikes and studs, are integrated. The traction elements may be integrally connected with the reinforcement plates; however, they may also be connected with the reinforcement plates so as to be exchangeable and, hence, detachable. With the assistance of the reinforcement plates, the application of pressure on the sole caused by the individual spikes or studs is to be distributed across a larger surface area in order to avoid painful straining points on the athlete""s feet.
Inherent in the sports shoes or soles known from the aforementioned prior art is the disadvantage that they can only be equipped with one type of traction elements each, either only with screw-in studs, or only with cams or only with spikes. Having such shoes, it is very difficult for e.g. a professional soccer player to safely play both on soft grass fields and on hard sand fields. This means that the player needs a special pair of shoes for each subsoil condition, the traction elements of which are specifically adapted to the respective condition of the field, so that in each case there are needed shoes which are equipped in a different manner for a dry and humid lawn as well as for dry and humid hard fields.
In order to remedy this disadvantage, the invention is based on the object to provide sports shoes with a sole that can be interchangeably equipped with different sets of traction elements of the most different type, so that depending on the condition of the field one and the same shoe can be equipped either with studs, cams or spikes, or also with clamping jaws that have a large surface area and extend transversely across the entire width of the sole.
This object is solved according to the invention in a sports shoe of the type initially mentioned in that the at least one carrier surface has such a geometric shape and the threaded inserts in the at least one carrier surface are positioned such that several interchangeable sets of different traction elements are able to be screwed into the threaded inserts.
Thereby it is achieved that a sportsman, in particular a professional soccer player, not only finds shoes for a specific ground condition which are ideal for him, whilst with a changed condition of the field he has to look for trade-offs between comfort of the shoe and functionality of the sole, but due to the invention is able to adapt his personally optimal shoe to varying conditions of the field and ground compositions in that he exchanges the available set of traction elements completely by another set of traction elements of a different kind. This interchangement feature significantly reduces, on the one hand, the costs for the respective athlete or player; above all, there is no longer a need for the player to get involved in trade-offs with varying conditions of the field, but he can play with his personally optimal pair of shoes both on grass fields and hard fields, on dry and on wet fields with optimum safety.
Preferably, the at least one carrier surface which is configured raised is formed in one piece with the sole made of plastic, because this reduces the production costs, but above all immovably fixes the carrier surfaces. The at least one carrier surface preferably extends across the entire width of the sole, so that all conceivable geometries of traction elements can be interchangeably and, hence, detachably fastened to the carrier surface.
In a preferred embodiment of the invention, the traction elements of a first set of such elements fully cover the at least one carrier surface, whilst the traction elements of a second set only partially cover the carrier surface(s). With such different sets of traction elements, the sports shoe offers a reliable grip on almost all grounds and field conditions.
Preferably, there is provided close to the distal and proximal longitudinal edges of the sole in each carrier surface at least one threaded insert each, i.e. at least two threaded inserts per carrier surface. The carrier surfaces may also be equipped with more than two threaded inserts, but not each of these additional threaded inserts having to be equipped with a traction element with each ground condition. Threaded inserts that are not used are preferably covered by a plastic cap or a screw closure, in order to protect the internal thread of the insert against soiling.
In one embodiment of the sports shoe according to the invention, the traction elements consist of a set of screw-in studs, cams or spikes, of which each screw-in stud, cam or spike comprises a threaded bolt capable of being screwed into the threaded inserts. The screw-in studs preferably comprise a collar in the shape of a truncated cone, the larger base circular area of which is adapted to the extent of the at least one carrier surface, so that the base circular area has an all-over, snug fit at the carrier surface without any gap, if the screw-in stud is screwed completely into the threaded insert.
In a further embodiment of the sports shoe according to the invention, the traction elements consist of a set of clamping jaws which extend across the entire width of the sole and comprise a mounting surface adapted to the geometric shape of the at least one carrier surface as well as through-holes for receiving fastening screws, the through-holes being registered with the threaded inserts. xe2x80x9cBeing registeredxe2x80x9d means that the through-holes not only are aligned with the threaded inserts, but also that there are aligned threaded inserts at those places where through-holes are arranged, and vice versa.
The clamping jaws preferably taper with increasing distance from the surface of the sole, to be precise, starting from their mounting surface. Thus, directly adjacent to the respectively associated carrier surface the wall thickness of the clamping jaws is the largest, and decreases with an increasing distance from the sole""s surface. In the region of their maximum distance from the sole""s surface, the clamping jaws preferably form narrow webs which would contact the ground exclusively, if shoe or sole could not sink in the ground. These webs, which are situated at a maximum distance from the sole""s surface, are preferably only formed at the edges of the sole, i.e. only at places close to the lateral and medial longitudinal edges of the sole, and not in the sole center, in the region of the center of the shoe tip and in the region of the center of the heel.
In a further preferred embodiment of the sports shoe according to the invention, the at least one carrier surface and the mounting surfaces of the clamping jaws are configured so as to be H-, U-, V- or horseshoe-shaped, with the legs or xe2x80x9cextremitiesxe2x80x9d of these geometric shapes being adapted to the natural curvatures of the distal and proximal longitudinal edges and the rounded portions in the region of the shoe tip and the heel.
The traction elements are preferably made of metal, plastic, fiber-reinforced or whisker-reinforced plastic, ceramics or composite materials of one or more of these materials. The traction elements are preferably made of a composite material including an elastomer component, because then an optimal trade-off can be achieved between fracture toughness, strength and elasticity.
Particularly preferred materials for the traction elements are cast aluminum and/or a titanium-aluminum precision casting alloy.
If the at least one carrier surface, which is configured raised, and the traction elements are dyed, and if the sole, the carrier surface(s) and the traction elements are dyed preferably with different colors, then it is readily possible to associate different sets of different traction elements to specific application purposes, which makes it easier for the wearer of the sports shoe to choose the different sets of traction elements for different grounds.